Design of a 175 GHz SiGe-based voltage-controlled oscillator with greater than 7.6 dBm power
IJICTJOURNAL
0 views
12 slides
Oct 07, 2025
Slide 1 of 12
1
2
3
4
5
6
7
8
9
10
11
12
About This Presentation
In this research, we present a low phase noise (PN) and wide tuning range 175 GHz inductors and capacitors (LC) voltage-controlled oscillator (VCO) based on a differential Colpitts oscillator that was designed using a 0.13 μm bipolar complementary metal oxide semiconductor (BiCMOS) and simulated. T...
Slide Content
International Journal of Informatics and Communication Technology (IJ-ICT)
Vol. 12, No. 2, August 2023, pp. 103~114
ISSN: 2252-8776, DOI: 10.11591/ijict.v12i2.pp103-114 103
Journal homepage: http://ijict.iaescore.com
Design of a 175 GHz SiGe-based voltage-controlled oscillator
with greater than 7.6 dBm power
Oluseun Damilola Oyeleke
1,2
, Aliyu Danjuma Usman
2
, Kabir Ahmad Abubilal
2
, Habeeb Bello
2
,
Olabode Idowu-Bismark
3
1
Department of Computer Engineering, Nile University of Nigeria, Abuja, Nigeria
2
Department of Electronic and Telecommunication Engineering, Ahmadu Bello University, Zaria, Nigeria
3
Department of Electrical and Information Engineering, Covenant University, Ota, Nigeria
Article Info ABSTRACT
Article history:
Received Nov 8, 2022
Revised Nov 28, 2022
Accepted Dec 30, 2022
In this research, we present a low phase noise (PN) and wide tuning range
175 GHz inductors and capacitors (LC) voltage-controlled oscillator (VCO)
based on a differential Colpitts oscillator that was designed using a 0.13 μm
bipolar complementary metal oxide semiconductor (BiCMOS) and
simulated. The square of the tank Q-factor and the square of the oscillation
amplitude were both maximized to reduce PN. With an extensive
examination of parasitic, mathematical analysis of load impedances, and
implementation of differential design, the PN was reduced, and the output
power was enhanced. Using a supply voltage of 1.6 V, the VCO consumes
41.9 mA, resulting in a total power usage of 67 mW to prevent undesirable
PN deterioration, an inter-stage LC filter at the VCO-buffer interface
increases the swing at the buffer input. To make a better output, a buffer is
used to isolate the load from the VCO core. In addition, the VCO has a high
linearity and the overall, the VCO presented in this study demonstrates
excellent performance and has the potential to be used in a wide range of
applications that require a high-performance, low-power VCO.
Keywords:
Colpitts oscillator
Microwave
SiGe 130 nm
Terahertz
Voltage-controlled oscillator
This is an open access article under the CC BY-SA license.
Corresponding Author:
Olabode Idowu-Bismark
Department of Electrical and Information Engineering, Covenant University
Ota, Ogun State, Nigeria
Email: [email protected]
1. INTRODUCTION
The terahertz (THz) spectrum is the next frontier for efficient imaging applications [1], [2] and high-
bandwidth wireless communication [3]. THz radiation has a greater spatial resolution for imaging and
sensing than lower-frequency radio and millimeter waves due to its shorter wavelength [4], [5]. Another
notable aspect is that the permittivity of various materials can be determined by measuring their spectral
response to THz radiation. As more applications are being explored and deployed at THz frequencies, there
will be a demand for devices able to generate and amplify signals at THz frequencies. One of the major
obstacles to achieving any of the uses is the creation of high-power, integrated THz sources that operate
inside the THz atmospheric transmission windows [6]. For the realization of these THz cameras, high
powered signal sources are necessary.
The seventh framework programme (FP7) for research and technology, 700 GHz has been identified
by European commission development as a promising solution for mmWave imaging and sensing [7].
Terasense, a leading company in THz imaging identified the 700 GHz region as a part of the electromagnetic
(EM) frequency spectrum where most common materials are transparent to THz radiation. A previous
researcher’s goal was to use common-mode impedance enhancement to construct a 300 GHz Silicon-
Vol. 12, No. 2, August 2023, pp. 103~114
ISSN: 2252-8776, DOI: 10.11591/ijict.v12i2.pp103-114 103
Journal homepage: http://ijict.iaescore.com
Design of a 175 GHz SiGe-based voltage-controlled oscillator
with greater than 7.6 dBm power
Oluseun Damilola Oyeleke
1,2
, Aliyu Danjuma Usman
2
, Kabir Ahmad Abubilal
2
, Habeeb Bello
2
,
Olabode Idowu-Bismark
3
1
Department of Computer Engineering, Nile University of Nigeria, Abuja, Nigeria
2
Department of Electronic and Telecommunication Engineering, Ahmadu Bello University, Zaria, Nigeria
3
Department of Electrical and Information Engineering, Covenant University, Ota, Nigeria
Article Info ABSTRACT
Article history:
Received Nov 8, 2022
Revised Nov 28, 2022
Accepted Dec 30, 2022
In this research, we present a low phase noise (PN) and wide tuning range
175 GHz inductors and capacitors (LC) voltage-controlled oscillator (VCO)
based on a differential Colpitts oscillator that was designed using a 0.13 μm
bipolar complementary metal oxide semiconductor (BiCMOS) and
simulated. The square of the tank Q-factor and the square of the oscillation
amplitude were both maximized to reduce PN. With an extensive
examination of parasitic, mathematical analysis of load impedances, and
implementation of differential design, the PN was reduced, and the output
power was enhanced. Using a supply voltage of 1.6 V, the VCO consumes
41.9 mA, resulting in a total power usage of 67 mW to prevent undesirable
PN deterioration, an inter-stage LC filter at the VCO-buffer interface
increases the swing at the buffer input. To make a better output, a buffer is
used to isolate the load from the VCO core. In addition, the VCO has a high
linearity and the overall, the VCO presented in this study demonstrates
excellent performance and has the potential to be used in a wide range of
applications that require a high-performance, low-power VCO.
Keywords:
Colpitts oscillator
Microwave
SiGe 130 nm
Terahertz
Voltage-controlled oscillator
This is an open access article under the CC BY-SA license.
Corresponding Author:
Olabode Idowu-Bismark
Department of Electrical and Information Engineering, Covenant University
Ota, Ogun State, Nigeria
Email: [email protected]
1. INTRODUCTION
The terahertz (THz) spectrum is the next frontier for efficient imaging applications [1], [2] and high-
bandwidth wireless communication [3]. THz radiation has a greater spatial resolution for imaging and
sensing than lower-frequency radio and millimeter waves due to its shorter wavelength [4], [5]. Another
notable aspect is that the permittivity of various materials can be determined by measuring their spectral
response to THz radiation. As more applications are being explored and deployed at THz frequencies, there
will be a demand for devices able to generate and amplify signals at THz frequencies. One of the major
obstacles to achieving any of the uses is the creation of high-power, integrated THz sources that operate
inside the THz atmospheric transmission windows [6]. For the realization of these THz cameras, high
powered signal sources are necessary.
The seventh framework programme (FP7) for research and technology, 700 GHz has been identified
by European commission development as a promising solution for mmWave imaging and sensing [7].
Terasense, a leading company in THz imaging identified the 700 GHz region as a part of the electromagnetic
(EM) frequency spectrum where most common materials are transparent to THz radiation. A previous
researcher’s goal was to use common-mode impedance enhancement to construct a 300 GHz Silicon-
ISSN: 2252-8776
Int J Inf & Commun Technol, Vol. 12, No. 2, August 2023: 103-114
104
Germanium (SiGe-based) high-performance push-pull voltage-controlled oscillator (VCO) with >1-mW peak
power output, which is a novel way of enhancing the efficiency and power output THz signal sources and
millimeter-wave and. To greatly increase the harmonic power output compared to a conventional method,
this research will demonstrate two push-push VCOs based on a unique method for achieving a common-
mode resonance in a Colpitts push-push oscillator circuit. The VCOs discussed Wallace et al. [8] operate
between 292 and 0.318 THz and 0.305 and 0.327 THz, respectively, with peak power outputs of 1.15 and
1.05 mW and an 8% tuning range. This outputs power and tuning range needs improvement to overcome
penetration attenuation in body area networks. To be utilized for high-resolution imaging.
Research by Vafapour et al. [9] aim to come up with a strategy for creating small, millimeter-wave
fundamental oscillators with high efficiency that operate above the active device's fmax/2 to optimize
oscillator output strength. An iterative strategy based on load and source-pull techniques was employed to
optimize the amplifier's power output. However, the 65 nm complementary metal oxide semiconductor
(CMOS) process was appropriate for applications with low power (LP) options because its gate has a
nominal operating voltage of 1.2 V which is a LP option when in comparison with other different foundries
90 nm LP, 90 nm general purpose (GP), and 130 nm GP processes. 65 nm CMOS performance was also
degraded by temperature variations.
Research by Chiang et al. [10] using analog integrated circuits, this study discusses the construction of
a quadrature VCO (QVCO) that can create offset frequencies of positive and negative alterations, as well as
zero frequency. It had two integrator loop oscillators and was one of the simplest quadrature-phase oscillator
types. Each integrator adjusts the phase by 90 degrees, while negative feedback shifts it by 180 degrees, for a
complete 360 degrees phase shift around the loop. However, a major drawback of using a transconductance
capacitor was its difficulty in the implementation of a rail-to-rail input capability. (A rail-to-rail output was an
output where the value of the output can be the entire range of the power supply) the power consumption can be
improved by using SiGe semiconductor processes. Also, the tuning scheme of this transconductance capacitor
to achieve good precision was challenging and hence also increases their complexities in implementation.
According to Momeni and Afshari [11] the series-coupled QVCO (SQVCO) was proposed as a
modification to the SQVCO to decrease phase noise (PN) in the VCO. To ensure that the switching transistor
also affects the tank’s rising edge current pulse, hence small capacitors must be added to each cell. However,
even employing coupled oscillators, the maximum tuning range was still relatively limited, necessitating the
usage of many VCO cores to provide sufficient power output. Research by Voinigescu [12] developed a
different fundamental frequency VCO with a 176 GHz central frequency. High power output, low PN, strong
linearity, and compacted sizes are among the benefits of the chosen architecture, which is paired with the
usage of a Colpitts topology based on common emitters. The tuning bandwidth was 8.5, PN was 110 at 10,
maximum power output was 7.3 dBm, maximum output variation was 1.7 dBm, DC power was 82 mW,
maximum efficiency was 6.6, and chip measurements were 0.30×0.35. The tuning range, PN maximum
performance, and power output can all be enhanced to roughly 100 mW.
Considering the limitations of the reviews made, the aim of this paper, therefore, is to design, model
and simulate a VCO with a PN<-100 at 10 MHz dB/Hz, >7 dBm power output, >3% tuning range at
175 GHz based on the fully-differential, push-push, Colpitts topology. Additional works will extract the 4
th
harmonic signal from 175 GHz to build a 700 GHz signal generator for imaging. The contribution of this
work is to achieve a power output of greater than 7.6 dBm, PN of -73 at 10 MHz offset, a tuning range of
11.9% and a power consumption of 67.18 mW results were achieved.
2. PROPOSED METHOD
A promising scheme to obtain radio frequency (RF) power at 700 GHz is to utilize a low PN
G-band-wave oscillator with a high-performance amplifier/multiplier chain. Figure 1 shows the block
diagram conceptual model of the proposed integrated 700 GHz generator. The choice of the target frequency
is based on the frequency at which objects are transparent to THz signals.
175 GHZ SSPA
175GHZ VCO
INTERSTAGE
MATCHING
700GHZ Vout
4X FREQUENCY
MULTIPLIER
INTERSTAGE
MATCHING
Figure 1. Conceptual design of a 700 GHz signal source
Int J Inf & Commun Technol, Vol. 12, No. 2, August 2023: 103-114
104
Germanium (SiGe-based) high-performance push-pull voltage-controlled oscillator (VCO) with >1-mW peak
power output, which is a novel way of enhancing the efficiency and power output THz signal sources and
millimeter-wave and. To greatly increase the harmonic power output compared to a conventional method,
this research will demonstrate two push-push VCOs based on a unique method for achieving a common-
mode resonance in a Colpitts push-push oscillator circuit. The VCOs discussed Wallace et al. [8] operate
between 292 and 0.318 THz and 0.305 and 0.327 THz, respectively, with peak power outputs of 1.15 and
1.05 mW and an 8% tuning range. This outputs power and tuning range needs improvement to overcome
penetration attenuation in body area networks. To be utilized for high-resolution imaging.
Research by Vafapour et al. [9] aim to come up with a strategy for creating small, millimeter-wave
fundamental oscillators with high efficiency that operate above the active device's fmax/2 to optimize
oscillator output strength. An iterative strategy based on load and source-pull techniques was employed to
optimize the amplifier's power output. However, the 65 nm complementary metal oxide semiconductor
(CMOS) process was appropriate for applications with low power (LP) options because its gate has a
nominal operating voltage of 1.2 V which is a LP option when in comparison with other different foundries
90 nm LP, 90 nm general purpose (GP), and 130 nm GP processes. 65 nm CMOS performance was also
degraded by temperature variations.
Research by Chiang et al. [10] using analog integrated circuits, this study discusses the construction of
a quadrature VCO (QVCO) that can create offset frequencies of positive and negative alterations, as well as
zero frequency. It had two integrator loop oscillators and was one of the simplest quadrature-phase oscillator
types. Each integrator adjusts the phase by 90 degrees, while negative feedback shifts it by 180 degrees, for a
complete 360 degrees phase shift around the loop. However, a major drawback of using a transconductance
capacitor was its difficulty in the implementation of a rail-to-rail input capability. (A rail-to-rail output was an
output where the value of the output can be the entire range of the power supply) the power consumption can be
improved by using SiGe semiconductor processes. Also, the tuning scheme of this transconductance capacitor
to achieve good precision was challenging and hence also increases their complexities in implementation.
According to Momeni and Afshari [11] the series-coupled QVCO (SQVCO) was proposed as a
modification to the SQVCO to decrease phase noise (PN) in the VCO. To ensure that the switching transistor
also affects the tank’s rising edge current pulse, hence small capacitors must be added to each cell. However,
even employing coupled oscillators, the maximum tuning range was still relatively limited, necessitating the
usage of many VCO cores to provide sufficient power output. Research by Voinigescu [12] developed a
different fundamental frequency VCO with a 176 GHz central frequency. High power output, low PN, strong
linearity, and compacted sizes are among the benefits of the chosen architecture, which is paired with the
usage of a Colpitts topology based on common emitters. The tuning bandwidth was 8.5, PN was 110 at 10,
maximum power output was 7.3 dBm, maximum output variation was 1.7 dBm, DC power was 82 mW,
maximum efficiency was 6.6, and chip measurements were 0.30×0.35. The tuning range, PN maximum
performance, and power output can all be enhanced to roughly 100 mW.
Considering the limitations of the reviews made, the aim of this paper, therefore, is to design, model
and simulate a VCO with a PN<-100 at 10 MHz dB/Hz, >7 dBm power output, >3% tuning range at
175 GHz based on the fully-differential, push-push, Colpitts topology. Additional works will extract the 4
th
harmonic signal from 175 GHz to build a 700 GHz signal generator for imaging. The contribution of this
work is to achieve a power output of greater than 7.6 dBm, PN of -73 at 10 MHz offset, a tuning range of
11.9% and a power consumption of 67.18 mW results were achieved.
2. PROPOSED METHOD
A promising scheme to obtain radio frequency (RF) power at 700 GHz is to utilize a low PN
G-band-wave oscillator with a high-performance amplifier/multiplier chain. Figure 1 shows the block
diagram conceptual model of the proposed integrated 700 GHz generator. The choice of the target frequency
is based on the frequency at which objects are transparent to THz signals.
175 GHZ SSPA
175GHZ VCO
INTERSTAGE
MATCHING
700GHZ Vout
4X FREQUENCY
MULTIPLIER
INTERSTAGE
MATCHING
Figure 1. Conceptual design of a 700 GHz signal source
Int J Inf & Commun Technol ISSN: 2252-8776
Design of a 175 GHz SiGe-based voltage-controlled oscillator with greater … (Oluseun Damilola Oyeleke)
105
This paper’s focus is the development of block one (VCO) of this approach. In realization of the
VCO, a differential Colpitts oscillator with power-combined output will be designed and simulated. The
figure of merit critical to the efficiency of the VCO is the output power, PN, and tuning range, and hence
design will be optimized to maximize these parameters. The steps followed to realize this is parameter
extraction of the transistor model, determination of effective impedance, resonant frequency parameters, and
reduction of PN.
3. METHOD
3.1. Parameter extraction analysis
It will be impossible to build a VCO at such a high frequency without substantive parameter
analysis. One of the main effects of parasitics at high frequency is an increase in the oscillation frequency
which causes fluactuations, an increase in the PN of the VCO and parasitics can also increase the power
consumption of the VCO at high frequencies. This is because parasitics can cause additional current to flow
through the circuit, increasing the power consumption of the VCO. Overall, it is important to carefully
consider the impact of parasitics in high frequency VCO design. The parametric extraction utilized in this
research is shown in Table 1.
Table 1. The small-signal equivalent-circuit parameters [13], [14]
Symbol Description Value Unit
�
?????? Small-signal base-emitter resistance 12 Ω
�
� Base spreading resistance 3 Ω
�
??????(�
��) Base-emitter capacitance 7 fF
�
�(�
��) Base-collector capacitance 15 fF
�
��� Varactor capacitance 50 fF
�
������ Common-mode resonant capacitance 16 fF
�
� Base tank inductance 20 pH
�
� Small signal transconductance 420 mS
�
� Transit frequency 300 GHz
�
�??????�� Bias current 40 mA
3.2. Determination of the effective input impedance
In the determination of the effective input impedance of the Colpitts oscillator with parasitics and
effective negative resistance for sustained oscillation to determine the overall input impedance of the VCO.
The impedances of all active and passive elements are presented. A small equivalent circuit of the
heterojunction bipolar transistor (HBT) and a high-frequency equivalent model of the VCO half-circuit
shown in schematic simplified for analysis is shown in Figure 2. For ease of derivation of the input
impedance Z_in, alphabets were assigned to parameters as presented in Table 2 to ensure the equation
derived is accurate.
A B
E
HBase
Collector
Emitter junction
G
Figure 2. Equivalent model of a high-frequency VCO half-circuit
Design of a 175 GHz SiGe-based voltage-controlled oscillator with greater … (Oluseun Damilola Oyeleke)
105
This paper’s focus is the development of block one (VCO) of this approach. In realization of the
VCO, a differential Colpitts oscillator with power-combined output will be designed and simulated. The
figure of merit critical to the efficiency of the VCO is the output power, PN, and tuning range, and hence
design will be optimized to maximize these parameters. The steps followed to realize this is parameter
extraction of the transistor model, determination of effective impedance, resonant frequency parameters, and
reduction of PN.
3. METHOD
3.1. Parameter extraction analysis
It will be impossible to build a VCO at such a high frequency without substantive parameter
analysis. One of the main effects of parasitics at high frequency is an increase in the oscillation frequency
which causes fluactuations, an increase in the PN of the VCO and parasitics can also increase the power
consumption of the VCO at high frequencies. This is because parasitics can cause additional current to flow
through the circuit, increasing the power consumption of the VCO. Overall, it is important to carefully
consider the impact of parasitics in high frequency VCO design. The parametric extraction utilized in this
research is shown in Table 1.
Table 1. The small-signal equivalent-circuit parameters [13], [14]
Symbol Description Value Unit
�
?????? Small-signal base-emitter resistance 12 Ω
�
� Base spreading resistance 3 Ω
�
??????(�
��) Base-emitter capacitance 7 fF
�
�(�
��) Base-collector capacitance 15 fF
�
��� Varactor capacitance 50 fF
�
������ Common-mode resonant capacitance 16 fF
�
� Base tank inductance 20 pH
�
� Small signal transconductance 420 mS
�
� Transit frequency 300 GHz
�
�??????�� Bias current 40 mA
3.2. Determination of the effective input impedance
In the determination of the effective input impedance of the Colpitts oscillator with parasitics and
effective negative resistance for sustained oscillation to determine the overall input impedance of the VCO.
The impedances of all active and passive elements are presented. A small equivalent circuit of the
heterojunction bipolar transistor (HBT) and a high-frequency equivalent model of the VCO half-circuit
shown in schematic simplified for analysis is shown in Figure 2. For ease of derivation of the input
impedance Z_in, alphabets were assigned to parameters as presented in Table 2 to ensure the equation
derived is accurate.
A B
E
HBase
Collector
Emitter junction
G
Figure 2. Equivalent model of a high-frequency VCO half-circuit
ISSN: 2252-8776
Int J Inf & Commun Technol, Vol. 12, No. 2, August 2023: 103-114
106
Table 2. Parameters for the derivation of total input impedance seen at the VCO
Parameters Alphabet assignment
??????�
�� �
�
?????? �
�||� �
??????�
���� �
�+(�+1)� �
??????�
�� �
??????
����� �
� �||�
??????�
��
−??????
1
??????�
��
??????�
��
−??????
1
??????�
��
�
−??????
??????
�
??????
??????�
� Base tank inductance
(????????????�
�)
�
� Base spreading inductance
�=
��
�+�
(1)
�=
��
�+�
+(�+1)� (2)
�=
�(��+??????(��+��+�+�))
�(�+�??????+??????+�)+�(�??????+??????+�)
(3)
??????
�����=
��
��(��
�??????�??????+��
??????
�
??????�????????????�????????????�??????��
��
�??????(�??????+��
??????
�
??????��??????
??????
�
??????��
�??????��
�??????��
(4)
??????
??????�=??????
�����+????????????�
�+�
� (5)
where, ??????
�����=�
�����+????????????
����� note that �
����� this is the real part ??????
����� which also includes �
�. A method
used to generate a negative resistance was by adding reactive elements from transmission lines at the base of
the transistor and hence total negative resistance which will develop at the base of the active device is:
�
−��=�
�����+�
� (6)
When the negative resistance is present, the requirement for oscillation is satisfied. At the oscillation
frequency, �
����� adjusts for resonator losses.
3.3. Determination of the resonant frequency parameters
To determine the resonant frequency based on the design of the Colpitts oscillator, a reduced tank
circuit schematic is shown for analysis as shown in Figure 3.
Q1
CQvar
Figure 3. Colpitts tank circuit with parasitic capacitances
For oscillation to occur all reactance must equal zero [15]:
??????
���+??????�??????�
�����=0 (7)
After some algebraic analysis, as (7) reduces to:
Int J Inf & Commun Technol, Vol. 12, No. 2, August 2023: 103-114
106
Table 2. Parameters for the derivation of total input impedance seen at the VCO
Parameters Alphabet assignment
??????�
�� �
�
?????? �
�||� �
??????�
���� �
�+(�+1)� �
??????�
�� �
??????
����� �
� �||�
??????�
��
−??????
1
??????�
��
??????�
��
−??????
1
??????�
��
�
−??????
??????
�
??????
??????�
� Base tank inductance
(????????????�
�)
�
� Base spreading inductance
�=
��
�+�
(1)
�=
��
�+�
+(�+1)� (2)
�=
�(��+??????(��+��+�+�))
�(�+�??????+??????+�)+�(�??????+??????+�)
(3)
??????
�����=
��
��(��
�??????�??????+��
??????
�
??????�????????????�????????????�??????��
��
�??????(�??????+��
??????
�
??????��??????
??????
�
??????��
�??????��
�??????��
(4)
??????
??????�=??????
�����+????????????�
�+�
� (5)
where, ??????
�����=�
�����+????????????
����� note that �
����� this is the real part ??????
����� which also includes �
�. A method
used to generate a negative resistance was by adding reactive elements from transmission lines at the base of
the transistor and hence total negative resistance which will develop at the base of the active device is:
�
−��=�
�����+�
� (6)
When the negative resistance is present, the requirement for oscillation is satisfied. At the oscillation
frequency, �
����� adjusts for resonator losses.
3.3. Determination of the resonant frequency parameters
To determine the resonant frequency based on the design of the Colpitts oscillator, a reduced tank
circuit schematic is shown for analysis as shown in Figure 3.
Q1
CQvar
Figure 3. Colpitts tank circuit with parasitic capacitances
For oscillation to occur all reactance must equal zero [15]:
??????
���+??????�??????�
�����=0 (7)
After some algebraic analysis, as (7) reduces to:
Int J Inf & Commun Technol ISSN: 2252-8776
Design of a 175 GHz SiGe-based voltage-controlled oscillator with greater … (Oluseun Damilola Oyeleke)
107
1
??????
=√(�
��)[
�
�??????��??????��
�
�??????+��??????��
] (8)
There is contact parasitic �
��� in series with �
�� and ignoring mutual inductance as (8) is recast as:
1
??????
=√(�
��+�
���)[
�
�??????��??????��
�
�??????+��??????��
] (9)
where, �
�� and �
�� are parasitic capacitances, ��
��� is varactor capacitance, with the condition in (9) met
and the values of L and C set the circuit will start oscillating at the center frequency of 175 GHz.
3.4. Estimation of the simplified fundamental oscillation condition negative resistance
The negative resistance generated by the transistors compensates for the resistive losses in the
passive parts, allowing the oscillation to continue (Q1 and Q2). In a VCO, an oscillator occurs when all
reactive components cancels and only real resistance between the LC tank circuit and resistance of the active
device are left in the system [16], [17]. To ensure that oscillation will occur and is sustained, the negative
resistance developed at the base of the transistor was carefully set. The small signal negative resistance at the
transistor's base can be expressed as [18], [19]:
�=ℜ(??????
??????�)=
−��
??????
2
�1�2
(10)
For a practical HBT, the total resistance required to supply negative resistance is made up of a summation of
�
���, �
�, and �
�, and hence as (10) can also be given in the form as (11) [20]:
R=
��
??????
���
2
��??????�??????�����
��
(11)
where, �
��� and �
��� are the parasitic impedances of the connections between the thick metal layers
typically employed for microstrips and the transistor contact layers, respectively. �
� and �
� are the series
resistance of transmission lines and transistor base spreading resistance. �
�?????? is the inductance of the
transmission line. This implies that the net resistance between the tank and the active device is almost equal
to 0 so that the active device produces resistance to compensate for the loss of resistance by the tank circuit.
if this is not done the oscillation is not sustainable.
3.5. Reduction of phase noise
In this section, the PN is reduced. The VCO PN is a function of the oscillation amplitude, �
1, the
�
1/�
2 ratio, and of �
�. The total equivalent input noise current of the transistor as given by [21].
�
��??????�??????
��??????�
=
|�
2
�|
??????
2
������
1
2
(
�1
�2
+1)
2
(12)
When �
1 is dominated by �
��, the bipolar junction transistor (BJT) transformation as (12) was given by [22].
�
��??????�??????
��
=
|�
2
�|
??????
2
����
2
�
�
2
�??????(
�
�??????
��??????��
2
(13)
where, ??????
��� is the tank voltage amplitude, �
��??????�� output noise power, �
� is the frequency offset, and �
�??????� is
the power of the carrier.
PN is in inverse proportionality to the square of the tank Q and the square of the oscillation
amplitude ??????
���, both were maximized. According to as (13), increasing the size of the HBT causes the
oscillation frequency to decrease. The VCO PN performance is determined by the values of �
?????? (which is
dominated by �
��) and �
���, as well as the oscillation amplitude and equivalent input noise current of the
HBT (�
�).
3.6. Selection of the voltage-controlled oscillator topology
The differential Colpitts topology was applied, as illustrated in Figure 4. The differential design is
more suited to integrated circuit implementations. Particularly where power supply noise and substrate noise
coupling are to be minimized.
Design of a 175 GHz SiGe-based voltage-controlled oscillator with greater … (Oluseun Damilola Oyeleke)
107
1
??????
=√(�
��)[
�
�??????��??????��
�
�??????+��??????��
] (8)
There is contact parasitic �
��� in series with �
�� and ignoring mutual inductance as (8) is recast as:
1
??????
=√(�
��+�
���)[
�
�??????��??????��
�
�??????+��??????��
] (9)
where, �
�� and �
�� are parasitic capacitances, ��
��� is varactor capacitance, with the condition in (9) met
and the values of L and C set the circuit will start oscillating at the center frequency of 175 GHz.
3.4. Estimation of the simplified fundamental oscillation condition negative resistance
The negative resistance generated by the transistors compensates for the resistive losses in the
passive parts, allowing the oscillation to continue (Q1 and Q2). In a VCO, an oscillator occurs when all
reactive components cancels and only real resistance between the LC tank circuit and resistance of the active
device are left in the system [16], [17]. To ensure that oscillation will occur and is sustained, the negative
resistance developed at the base of the transistor was carefully set. The small signal negative resistance at the
transistor's base can be expressed as [18], [19]:
�=ℜ(??????
??????�)=
−��
??????
2
�1�2
(10)
For a practical HBT, the total resistance required to supply negative resistance is made up of a summation of
�
���, �
�, and �
�, and hence as (10) can also be given in the form as (11) [20]:
R=
��
??????
���
2
��??????�??????�����
��
(11)
where, �
��� and �
��� are the parasitic impedances of the connections between the thick metal layers
typically employed for microstrips and the transistor contact layers, respectively. �
� and �
� are the series
resistance of transmission lines and transistor base spreading resistance. �
�?????? is the inductance of the
transmission line. This implies that the net resistance between the tank and the active device is almost equal
to 0 so that the active device produces resistance to compensate for the loss of resistance by the tank circuit.
if this is not done the oscillation is not sustainable.
3.5. Reduction of phase noise
In this section, the PN is reduced. The VCO PN is a function of the oscillation amplitude, �
1, the
�
1/�
2 ratio, and of �
�. The total equivalent input noise current of the transistor as given by [21].
�
��??????�??????
��??????�
=
|�
2
�|
??????
2
������
1
2
(
�1
�2
+1)
2
(12)
When �
1 is dominated by �
��, the bipolar junction transistor (BJT) transformation as (12) was given by [22].
�
��??????�??????
��
=
|�
2
�|
??????
2
����
2
�
�
2
�??????(
�
�??????
��??????��
2
(13)
where, ??????
��� is the tank voltage amplitude, �
��??????�� output noise power, �
� is the frequency offset, and �
�??????� is
the power of the carrier.
PN is in inverse proportionality to the square of the tank Q and the square of the oscillation
amplitude ??????
���, both were maximized. According to as (13), increasing the size of the HBT causes the
oscillation frequency to decrease. The VCO PN performance is determined by the values of �
?????? (which is
dominated by �
��) and �
���, as well as the oscillation amplitude and equivalent input noise current of the
HBT (�
�).
3.6. Selection of the voltage-controlled oscillator topology
The differential Colpitts topology was applied, as illustrated in Figure 4. The differential design is
more suited to integrated circuit implementations. Particularly where power supply noise and substrate noise
coupling are to be minimized.
ISSN: 2252-8776
Int J Inf & Commun Technol, Vol. 12, No. 2, August 2023: 103-114
108 Q2Q1
Q1 Q1
L1
L5
L3
L2
L6
L4
Figure 4. Fully differential voltage control Colpitts oscillator architecture
A differential topology has benefits in terms of quality factor and tuning range, and by power
combining, additional 3 dB power can be obtained. The designed VCO core shown in Figure 5 comprises
transistors Q1, and Q2 and the resonator, which is composed of an inductor �
3,4. Which includes the
parasitics contacts and an effective capacitance. An oscillator with a tank circuit is formed by a connection of
matched transistors in a differential arrangement. The tuning voltage at the base of Qv1 and Qv2 is used to
alter their capacitances and provide a wide tuning range. The SG132 HBT active device was utilized to
provide a quantity of energy that was equal to the energy dissipated, allowing the circuit to maintain
oscillations.
3.7. Design of output buffer design
The buffer was realized with a simple common collector scheme as shown in Figure 5. The buffer
helps provide separation between the external load and VCO core and VCO pulling, like pushing, was kept to
a minimum topology with built-in isolation between the VCO tank and the load hereby providing a strong
reverse-isolation. The buffer is completely symmetrical. The VCO core and the buffer are both powered at
the same voltage. Because the voltage supply was kept as low as possible, an output buffer stage and separate
VCO core were used instead of the typical stacked buffer technique (1.6 V). At these frequencies, VCOs are
commonly constructed without output buffers, which provides excellent performance without significantly
affecting power consumption and allows for the use of a lower bias voltage, enhancing the monolithic
microwave integrated circuit (MMIC) system integration.
Q2
L8L7
Q2
Vout
Vout
VCO CORE
Figure 5. VCO buffer design
Int J Inf & Commun Technol, Vol. 12, No. 2, August 2023: 103-114
108 Q2Q1
Q1 Q1
L1
L5
L3
L2
L6
L4
Figure 4. Fully differential voltage control Colpitts oscillator architecture
A differential topology has benefits in terms of quality factor and tuning range, and by power
combining, additional 3 dB power can be obtained. The designed VCO core shown in Figure 5 comprises
transistors Q1, and Q2 and the resonator, which is composed of an inductor �
3,4. Which includes the
parasitics contacts and an effective capacitance. An oscillator with a tank circuit is formed by a connection of
matched transistors in a differential arrangement. The tuning voltage at the base of Qv1 and Qv2 is used to
alter their capacitances and provide a wide tuning range. The SG132 HBT active device was utilized to
provide a quantity of energy that was equal to the energy dissipated, allowing the circuit to maintain
oscillations.
3.7. Design of output buffer design
The buffer was realized with a simple common collector scheme as shown in Figure 5. The buffer
helps provide separation between the external load and VCO core and VCO pulling, like pushing, was kept to
a minimum topology with built-in isolation between the VCO tank and the load hereby providing a strong
reverse-isolation. The buffer is completely symmetrical. The VCO core and the buffer are both powered at
the same voltage. Because the voltage supply was kept as low as possible, an output buffer stage and separate
VCO core were used instead of the typical stacked buffer technique (1.6 V). At these frequencies, VCOs are
commonly constructed without output buffers, which provides excellent performance without significantly
affecting power consumption and allows for the use of a lower bias voltage, enhancing the monolithic
microwave integrated circuit (MMIC) system integration.
Q2
L8L7
Q2
Vout
Vout
VCO CORE
Figure 5. VCO buffer design
Int J Inf & Commun Technol ISSN: 2252-8776
Design of a 175 GHz SiGe-based voltage-controlled oscillator with greater … (Oluseun Damilola Oyeleke)
109
3.8. Designing of varactors for voltage-controlled oscillator tuning range
To achieve wider frequency operations and take advantage of the available bandwidth, the oscillator
was designed to cover the center frequencies of each channel with some margin. The usage of varactors to
cover the bandwidth provides an easy answer to this tuning range requirement. A big varactor would
diminish the tank's quality factor and therefore the PN because the varactor loss is considerable at mm-waves
due to huge ohmic losses. The variable capacitance in this design was obtained by connecting two transistors
Q1 (Qvar5 and Qvar6) with short-circuited base-emitter junctions to create back-to-back diode configuration as
shown in Figure 6 in an anti-series configuration, which improves the Colpitts VCO's tunability and linearity.
With dimensions of 0.07×6.3×7 µm
2
each. The varactor takes an input voltage of 800 mV and 16 pA which
makes the VCO tunable with low voltage and power consumption. Furthermore, each of these transistors is
constructed at the layout level using a pair of parallel transistors using the same dimensions as Q1 and Q2 to
reduce losses caused by the resonator tank.
Figure 6. 175 GHz varactor design
3.9. Designing of the final circuit diagram of voltage-controlled oscillator
A differential structure has advantages in terms of quality factor and tuning range, and power
combining can provide an additional 3 dB of power. Because it was designed with a differential architecture,
the circuit layout is precisely symmetrical as shown in Figure 7, and because the active device is biased to
have negative resistance, the overall resistance of the resulting parallel resonant circuit is negative. Q1 and
Q2 are sized and biased individually for the best noise and oscillation amplitude. The final layout of the VCO
is shown in Figure 8.
Q2Q1
Q1 Q1
L1
L5
L3
L2
L6
L4
Q2
L8L7
Q2
Vout
Vout
Figure 7. Complete 175 GHz differential VCO design
Design of a 175 GHz SiGe-based voltage-controlled oscillator with greater … (Oluseun Damilola Oyeleke)
109
3.8. Designing of varactors for voltage-controlled oscillator tuning range
To achieve wider frequency operations and take advantage of the available bandwidth, the oscillator
was designed to cover the center frequencies of each channel with some margin. The usage of varactors to
cover the bandwidth provides an easy answer to this tuning range requirement. A big varactor would
diminish the tank's quality factor and therefore the PN because the varactor loss is considerable at mm-waves
due to huge ohmic losses. The variable capacitance in this design was obtained by connecting two transistors
Q1 (Qvar5 and Qvar6) with short-circuited base-emitter junctions to create back-to-back diode configuration as
shown in Figure 6 in an anti-series configuration, which improves the Colpitts VCO's tunability and linearity.
With dimensions of 0.07×6.3×7 µm
2
each. The varactor takes an input voltage of 800 mV and 16 pA which
makes the VCO tunable with low voltage and power consumption. Furthermore, each of these transistors is
constructed at the layout level using a pair of parallel transistors using the same dimensions as Q1 and Q2 to
reduce losses caused by the resonator tank.
Figure 6. 175 GHz varactor design
3.9. Designing of the final circuit diagram of voltage-controlled oscillator
A differential structure has advantages in terms of quality factor and tuning range, and power
combining can provide an additional 3 dB of power. Because it was designed with a differential architecture,
the circuit layout is precisely symmetrical as shown in Figure 7, and because the active device is biased to
have negative resistance, the overall resistance of the resulting parallel resonant circuit is negative. Q1 and
Q2 are sized and biased individually for the best noise and oscillation amplitude. The final layout of the VCO
is shown in Figure 8.
Q2Q1
Q1 Q1
L1
L5
L3
L2
L6
L4
Q2
L8L7
Q2
Vout
Vout
Figure 7. Complete 175 GHz differential VCO design
ISSN: 2252-8776
Int J Inf & Commun Technol, Vol. 12, No. 2, August 2023: 103-114
110
Figure 8. Differential power output1 (175.3 GHz and 4.834 dBm (3.04 mW))
3.10. Simulation setup
Advanced design system (ADS) keysight 2019. The IHP SG132 product development kit was used
for the simulation of the VCO. The parameters used for the design are presented in Table 3.
Table 3. Chosen parameter values for 175 GHz VCO design and simulation
Parameter Value Unit
Q1, Q2 (w×l) 0.07×0.09×8 μm
2
QVar5~6 (w×l) 0.07×0.09×9 μm
2
R >100 Ω
LB 20 pH
gm 33 mS
Ibias 42.6 mA
Vosc 919 mV
Vcc 1.6 V
L1,2 (l×w) 100×2 μm
2
L3,4 (l×w) 59.5×2 μm
2
L5,6 (l×w) 15×4 μm
2
L7,8 (l×w) 62×4 μm
2
4. RESULTS AND DISCUSSION
4.1. Results of power output
The circuit’s frequency response in Figure 8 reveals a peak power output of close to 5 dBm at
175 GHz. The differential output voltages are symmetrical which is very important to have balanced
operation and added power. An output-to-input power ratio of 2:1 translates into a gain of 3 dB when the
signal strength is doubled. The peak of 7.834 dBm output power is high, given the fact that the overall DC-
power consumption of the VCO is 67 mW only.
4.2. Results of phase noise
The VCO's PN performance which is a very important metric in the performance of a VCO was also
simulated; the simulated results are shown in Figure 9. In this case, the fundamental signal is at 175 GHz, and
the bias voltage is 1.6 V. A PN of -73.90 dBc/Hz was simulated with this arrangement at a frequency offset
of 10 MHz.
Int J Inf & Commun Technol, Vol. 12, No. 2, August 2023: 103-114
110
Figure 8. Differential power output1 (175.3 GHz and 4.834 dBm (3.04 mW))
3.10. Simulation setup
Advanced design system (ADS) keysight 2019. The IHP SG132 product development kit was used
for the simulation of the VCO. The parameters used for the design are presented in Table 3.
Table 3. Chosen parameter values for 175 GHz VCO design and simulation
Parameter Value Unit
Q1, Q2 (w×l) 0.07×0.09×8 μm
2
QVar5~6 (w×l) 0.07×0.09×9 μm
2
R >100 Ω
LB 20 pH
gm 33 mS
Ibias 42.6 mA
Vosc 919 mV
Vcc 1.6 V
L1,2 (l×w) 100×2 μm
2
L3,4 (l×w) 59.5×2 μm
2
L5,6 (l×w) 15×4 μm
2
L7,8 (l×w) 62×4 μm
2
4. RESULTS AND DISCUSSION
4.1. Results of power output
The circuit’s frequency response in Figure 8 reveals a peak power output of close to 5 dBm at
175 GHz. The differential output voltages are symmetrical which is very important to have balanced
operation and added power. An output-to-input power ratio of 2:1 translates into a gain of 3 dB when the
signal strength is doubled. The peak of 7.834 dBm output power is high, given the fact that the overall DC-
power consumption of the VCO is 67 mW only.
4.2. Results of phase noise
The VCO's PN performance which is a very important metric in the performance of a VCO was also
simulated; the simulated results are shown in Figure 9. In this case, the fundamental signal is at 175 GHz, and
the bias voltage is 1.6 V. A PN of -73.90 dBc/Hz was simulated with this arrangement at a frequency offset
of 10 MHz.
Int J Inf & Commun Technol ISSN: 2252-8776
Design of a 175 GHz SiGe-based voltage-controlled oscillator with greater … (Oluseun Damilola Oyeleke)
111
Figure 9. Simulated PN
4.3. Results of tuning range
The results presented showed the tunning range and the equivalent frequency variation according to
the tuning voltage range and the corresponding output power at each range. This shows the effectiveness of
using voltage to control frequencies. When biased at Vcc of 1.6 V, a tuning range between 0 to 3 V produces
a frequency variation of 168.9 to 180 GHz allowing the VCO to be able to sweep across a range of
bandwidth which is a very good property of a VCO.
At higher tuning states, the transistor-based variable resonator can achieve an enhanced quality
factor, which enhances the PN in general at THz frequencies. The output impedance measured will be used
for conjugate matching to the input impedance of the input stage of the solid-state power amplifier (SSPA).
The power, frequency, and tuning voltage of the VCO were simulated as shown in Figures 10 and 11 for
three distinct bias voltages of 1.2, 1.4, and 1.6 V for a tuning voltage range from 0 to 3 V.
Figure 10. Graph of Vtune vs frequency
Figure 11. Graph of Vtune vs power (dBm)
When biased with 0.8 V, the VCO begins to oscillate at the desired center frequency, even if, as
expected, the low supply voltage causes some variations in the characteristics of the VCO because the
transistor runs at diverse bias points, causing the transistor’s non-linear behavior to alter. In any event, as
shown in the following. The bias circuitry absorbs a little amount of electricity (up to 6 mA for the higher
bias voltage). The VCO's tuning curve is provided, and it reveals that, at a central frequency of 175.3 GHz, a
bandwidth of 11.9 GHz was successfully attained. With a voltage sweep of 0–1.6 V, this yields a tuning
range of 6.788%. Over the VCO’s total tuning range, the design aspect ensures that the power output stays
constant, or at least over the minimum needed value. The circuit consumes 42.6 mA with a supply voltage of
1.6 V, resulting in total power consumption of 68.18 mW. Given the VCO's overall DC-power consumption
of only 68.18 mW, the peak power output of 5.3 dBm is quite considerable. As shown in Figure 12, the
flatness or amplitude fluctuation of only 1.01 dBm at 1.6 V over frequency is excellent. The capacity to
Design of a 175 GHz SiGe-based voltage-controlled oscillator with greater … (Oluseun Damilola Oyeleke)
111
Figure 9. Simulated PN
4.3. Results of tuning range
The results presented showed the tunning range and the equivalent frequency variation according to
the tuning voltage range and the corresponding output power at each range. This shows the effectiveness of
using voltage to control frequencies. When biased at Vcc of 1.6 V, a tuning range between 0 to 3 V produces
a frequency variation of 168.9 to 180 GHz allowing the VCO to be able to sweep across a range of
bandwidth which is a very good property of a VCO.
At higher tuning states, the transistor-based variable resonator can achieve an enhanced quality
factor, which enhances the PN in general at THz frequencies. The output impedance measured will be used
for conjugate matching to the input impedance of the input stage of the solid-state power amplifier (SSPA).
The power, frequency, and tuning voltage of the VCO were simulated as shown in Figures 10 and 11 for
three distinct bias voltages of 1.2, 1.4, and 1.6 V for a tuning voltage range from 0 to 3 V.
Figure 10. Graph of Vtune vs frequency
Figure 11. Graph of Vtune vs power (dBm)
When biased with 0.8 V, the VCO begins to oscillate at the desired center frequency, even if, as
expected, the low supply voltage causes some variations in the characteristics of the VCO because the
transistor runs at diverse bias points, causing the transistor’s non-linear behavior to alter. In any event, as
shown in the following. The bias circuitry absorbs a little amount of electricity (up to 6 mA for the higher
bias voltage). The VCO's tuning curve is provided, and it reveals that, at a central frequency of 175.3 GHz, a
bandwidth of 11.9 GHz was successfully attained. With a voltage sweep of 0–1.6 V, this yields a tuning
range of 6.788%. Over the VCO’s total tuning range, the design aspect ensures that the power output stays
constant, or at least over the minimum needed value. The circuit consumes 42.6 mA with a supply voltage of
1.6 V, resulting in total power consumption of 68.18 mW. Given the VCO's overall DC-power consumption
of only 68.18 mW, the peak power output of 5.3 dBm is quite considerable. As shown in Figure 12, the
flatness or amplitude fluctuation of only 1.01 dBm at 1.6 V over frequency is excellent. The capacity to
ISSN: 2252-8776
Int J Inf & Commun Technol, Vol. 12, No. 2, August 2023: 103-114
112
generate a high-power, adjustable signal with extremely high efficiency is a fundamental characteristic of the
developed VCO. Table 4 shows a thorough comparison of the produced results with various literary
solutions.
Figure 12. Simulated differential power output against frequency
Table 4. Table of comparison of results
[23] [24] [25] [26] [27] [28] This work
Technology 130 nm SiGe
HBT
0.25 nm
SiGe
130 nm
SiGe HBT
130 nm SiGe
HBT
55 nm SiGe
HBT
130 nm SiGe
HBT
130 nm SiGe
HBT
Center frequency (GHz) 184 161 190.6 140 195 176 175.3
Tuning percentage (%) 2 4.7 NA NA 2 NA 6.788
Tuning bandwidth (GHz) NA NA 12.2 NA NA 8.5 11.9
PN @ (frequency offset)
MHz, dBc/Hz
NA -86 @1 −91 @ 10 -75 @1 98.6 @1 −110 @10 73.9 @ 10
Power output (dBm) -11 -20 3.2 -1.5 6.5 7.3 7.8
Chip dimension (mm
2
) NA NA 0.70×0.33 0.275 NA 0.30×0.35
Power consumption (mW) NA NA 16.2 47 25.8 82 68.18
5. CONCLUSION
Due to the vast uses in medical imaging that THz frequencies can provide, the design of a
differential 175 GHz SiGe-based VCO with greater than 7.6 dBm power was accomplished in this work. The
development of high-power, integrated THz sources that operate inside the THz atmospheric transmission
windows is one of the main challenges to attaining any of the uses. With an extensive examination of
parasitics, mathematical analysis of load impedances, and implementation of the differential design. The PN
was reduced, and the output power was enhanced. Simulations were performed using ADS keysight 2019 and
power out of 7.8 dBm, PN of -73 @ 10 MHz offset, a tuning range of 11.9% and power consumption of
68.18 mW results were achieved. This is an increment of 6.85% in power output, 40% in the tuning range,
17% reduction in DC power consumption, and 33% reduction in PN compared to the past works cited.
REFERENCES
[1] Z. Li, B. Qi, X. Zhang, S. Zeinolabedinzadeh, L. Sang, and J. D. Cressler, “A 0.32-THz SiGe imaging array with polarization
diversity,” IEEE Transactions on Terahertz Science and Technology, vol. 8, no. 2, pp. 215–223, Mar. 2018, doi:
10.1109/TTHZ.2017.2787958.
[2] A. J. Fitzgerald, E. Berry, N. N. Zinovev, G. C. Walker, M. A. Smith, and J. M. Chamberlain, “An introduction to medical
imaging with coherent terahertz frequency radiation,” Physics in Medicine and Biology, vol. 47, no. 7, pp. 67–84, Apr. 2002, doi:
10.1088/0031-9155/47/7/201.
[3] Y. Bai, “Improving resolution by the higher-order microscope imaging system with thermal light,” in 2014 XXXIth URSI General
Assembly and Scientific Symposium (URSI GASS), Aug. 2014, pp. 1–3, doi: 10.1109/URSIGASS.2014.6929412.
[4] K. B. Cooper et al., “A high-resolution imaging radar at 580 GHz,” IEEE Microwave and Wireless Components Letters, vol. 18,
no. 1, pp. 64–66, Jan. 2008, doi: 10.1109/LMWC.2007.912049.
[5] C. Hoyer, J. Wagner, and F. Ellinger, “A 60 GHz VCO with 654 MHz direct frequency modulation bandwidth in 0.13-μm SiGe
Int J Inf & Commun Technol, Vol. 12, No. 2, August 2023: 103-114
112
generate a high-power, adjustable signal with extremely high efficiency is a fundamental characteristic of the
developed VCO. Table 4 shows a thorough comparison of the produced results with various literary
solutions.
Figure 12. Simulated differential power output against frequency
Table 4. Table of comparison of results
[23] [24] [25] [26] [27] [28] This work
Technology 130 nm SiGe
HBT
0.25 nm
SiGe
130 nm
SiGe HBT
130 nm SiGe
HBT
55 nm SiGe
HBT
130 nm SiGe
HBT
130 nm SiGe
HBT
Center frequency (GHz) 184 161 190.6 140 195 176 175.3
Tuning percentage (%) 2 4.7 NA NA 2 NA 6.788
Tuning bandwidth (GHz) NA NA 12.2 NA NA 8.5 11.9
PN @ (frequency offset)
MHz, dBc/Hz
NA -86 @1 −91 @ 10 -75 @1 98.6 @1 −110 @10 73.9 @ 10
Power output (dBm) -11 -20 3.2 -1.5 6.5 7.3 7.8
Chip dimension (mm
2
) NA NA 0.70×0.33 0.275 NA 0.30×0.35
Power consumption (mW) NA NA 16.2 47 25.8 82 68.18
5. CONCLUSION
Due to the vast uses in medical imaging that THz frequencies can provide, the design of a
differential 175 GHz SiGe-based VCO with greater than 7.6 dBm power was accomplished in this work. The
development of high-power, integrated THz sources that operate inside the THz atmospheric transmission
windows is one of the main challenges to attaining any of the uses. With an extensive examination of
parasitics, mathematical analysis of load impedances, and implementation of the differential design. The PN
was reduced, and the output power was enhanced. Simulations were performed using ADS keysight 2019 and
power out of 7.8 dBm, PN of -73 @ 10 MHz offset, a tuning range of 11.9% and power consumption of
68.18 mW results were achieved. This is an increment of 6.85% in power output, 40% in the tuning range,
17% reduction in DC power consumption, and 33% reduction in PN compared to the past works cited.
REFERENCES
[1] Z. Li, B. Qi, X. Zhang, S. Zeinolabedinzadeh, L. Sang, and J. D. Cressler, “A 0.32-THz SiGe imaging array with polarization
diversity,” IEEE Transactions on Terahertz Science and Technology, vol. 8, no. 2, pp. 215–223, Mar. 2018, doi:
10.1109/TTHZ.2017.2787958.
[2] A. J. Fitzgerald, E. Berry, N. N. Zinovev, G. C. Walker, M. A. Smith, and J. M. Chamberlain, “An introduction to medical
imaging with coherent terahertz frequency radiation,” Physics in Medicine and Biology, vol. 47, no. 7, pp. 67–84, Apr. 2002, doi:
10.1088/0031-9155/47/7/201.
[3] Y. Bai, “Improving resolution by the higher-order microscope imaging system with thermal light,” in 2014 XXXIth URSI General
Assembly and Scientific Symposium (URSI GASS), Aug. 2014, pp. 1–3, doi: 10.1109/URSIGASS.2014.6929412.
[4] K. B. Cooper et al., “A high-resolution imaging radar at 580 GHz,” IEEE Microwave and Wireless Components Letters, vol. 18,
no. 1, pp. 64–66, Jan. 2008, doi: 10.1109/LMWC.2007.912049.
[5] C. Hoyer, J. Wagner, and F. Ellinger, “A 60 GHz VCO with 654 MHz direct frequency modulation bandwidth in 0.13-μm SiGe
Int J Inf & Commun Technol ISSN: 2252-8776
Design of a 175 GHz SiGe-based voltage-controlled oscillator with greater … (Oluseun Damilola Oyeleke)
113
BiCMOS,” in 2021 International Conference on Electrical, Computer, Communications and Mechatronics Engineering
(ICECCME), Oct. 2021, pp. 1–4, doi: 10.1109/ICECCME52200.2021.9591117.
[6] R. Bindiganavile and A. Tajalli, “A controllable KVCO ring VCO topology,” in 2021 IEEE International Midwest Symposium on
Circuits and Systems (MWSCAS), Aug. 2021, pp. 732–736, doi: 10.1109/MWSCAS47672.2021.9531824.
[7] J. Raab et al., “Ultrafast two-dimensional field spectroscopy of terahertz intersubband saturable absorbers,” Optics Express, vol.
27, no. 3, pp. 2248–2257, Feb. 2019, doi: 10.1364/OE.27.002248.
[8] M. B. Wallace, A. Wax, D. N. Roberts, and R. N. Graf, “Reflectance spectroscopy,” Gastrointestinal Endoscopy Clinics of North
America, vol. 19, no. 2, pp. 233–242, Apr. 2009, doi: 10.1016/j.giec.2009.02.008.
[9] Z. Vafapour, A. Keshavarz, and H. Ghahraloud, “The potential of terahertz sensing for cancer diagnosis,” Heliyon, vol. 6, no. 12,
pp. 1–8, Dec. 2020, doi: 10.1016/j.heliyon.2020.e05623.
[10] P.-Y. Chiang, O. Momeni, and P. Heydari, “A 200-GHz inductively tuned VCO with-7-dBm output power in 130-nm SiGe
BiCMOS,” IEEE Transactions on Microwave Theory and Techniques, vol. 61, no. 10, pp. 3666–3673, Oct. 2013, doi:
10.1109/TMTT.2013.2279779.
[11] O. Momeni and E. Afshari, “High power terahertz and millimeter-wave oscillator design: a systematic approach,” IEEE Journal
of Solid-State Circuits, vol. 46, no. 3, pp. 583–597, Mar. 2011, doi: 10.1109/JSSC.2011.2104553.
[12] S. Voinigescu, High-frequency integrated circuits. Cambridge: Cambridge University Press, 2013.
[13] M. Schroter et al., “The EU DOTSEVEN project: overview and results,” in 2016 IEEE Compound Semiconductor Integrated
Circuit Symposium (CSICS), Oct. 2016, pp. 1–4, doi: 10.1109/CSICS.2016.7751070.
[14] F. Ahmed, M. Furqan, B. Heinemann, and A. Stelzer, “0.3-THz SiGe-based high-efficiency push–push VCOs with> 1-mW peak
output power employing common-mode impedance enhancement,” IEEE Transactions on Microwave Theory and Techniques,
vol. 66, no. 3, pp. 1384–1398, Mar. 2018, doi: 10.1109/TMTT.2017.2767593.
[15] A. Bhat and N. Krishnapura, “26.3 A 25-to-38 GHz, 195 dB FoMT LC QVCO in 65 nm LP CMOS using a 4-port dual-mode
resonator for 5G radios,” in 2019 IEEE International Solid- State Circuits Conference-(ISSCC), Feb. 2019, pp. 412–414, doi:
10.1109/ISSCC.2019.8662502.
[16] L. Pantoli, H. Bello, G. Leuzzi, H. J. Ng, and D. Kissinger, “SiGe sub-THz VCOs design approach for imaging applications,” in
2020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC), Jul. 2020, pp. 1–3,
doi: 10.1109/INMMiC46721.2020.9160077.
[17] C.-C. Chuang and H.-K. Chiou, “A low phase noise X band class E power VCO in 0.25 μm GaN/SiC technology,” in 2021 IEEE
International Symposium on Radio-Frequency Integration Technology (RFIT), Aug. 2021, pp. 1–3, doi:
10.1109/RFIT52905.2021.9565205.
[18] G. Gonzalez, Foundations of oscillator circuit design. Norwood: Artech House, 2007.
[19] H. Wang, J. Chen, J. T. S. Do, H. Rashtian, and X. Liu, “High-efficiency millimeter-wave single-ended and differential
fundamental oscillators in CMOS,” IEEE Journal of Solid-State Circuits, vol. 53, no. 8, pp. 2151–2163, Aug. 2018, doi:
10.1109/JSSC.2018.2837863.
[20] S. Kong, H. Liu, Y. Shen, Y. Wu, Y. Yu, and K. Kang, “A 3.65-4.10 GHz class-C VCO with 189.1 DBC/hz FoM based on low
electromagnetic coupling,” in 2021 International Conference on Microwave and Millimeter Wave Technology (ICMMT), May
2021, pp. 1–3, doi: 10.1109/ICMMT52847.2021.9618554.
[21] Y. Z. M. Ibrahim, M. A. Y. Abdalla, and A. N. Mohieldin, “A 197 FOMT VCO with 34% tuning range for 5G applications in
45nm SOI technology,” in 2022 IEEE Radio and Wireless Symposium (RWS), Jan. 2022, pp. 108–110, doi:
10.1109/RWS53089.2022.9719977.
[22] P. Maheshwari, P. K. Sadhu, M. Deharia, N. Nambath, and S. Gupta, “A quadrature-phase voltage controlled oscillator for offset
phase and frequency compensation,” in 2018 31st International Conference on VLSI Design and 2018 17th International
Conference on Embedded Systems (VLSID), Jan. 2018, pp. 177–180, doi: 10.1109/VLSID.2018.58.
[23] F. Vogelsang, D. Starke, J. Wittemeier, H. Rucker, and N. Pohl, “A highly-efficient 120 GHz and 240 GHz signal source in a
SiGe-technology,” in 2020 IEEE BiCMOS and Compound Semiconductor Integrated Circuits and Technology Symposium
(BCICTS), Nov. 2020, pp. 1–4, doi: 10.1109/BCICTS48439.2020.9392945.
[24] Y. Zhao, B. Heinemann, and U. R. Pfeiffer, “Fundamental mode colpitts VCOs at 115 and 165-GHz,” in 2011 IEEE
Bipolar/BiCMOS Circuits and Technology Meeting, Oct. 2011, pp. 33–36, doi: 10.1109/BCTM.2011.6082744.
[25] D. Fritsche, S. Li, N. Joram, C. Carta, and F. Ellinger, “Design and characterization of a 190-GHz voltage-controlled oscillator,”
in 2016 46th European Microwave Conference (EuMC), Oct. 2016, pp. 493–496, doi: 10.1109/EuMC.2016.7824387.
[26] U. Ali, G. Fischer, and A. Thiede, “Low power fundamental VCO design in D-band using 0.13 μm SiGe BiCMOS technology,”
in 2015 German Microwave Conference, Mar. 2015, pp. 359–362, doi: 10.1109/GEMIC.2015.7107827.
[27] B. Khamaisi and E. Socher, “A 159-169 GHz frequency source with 1.26 mW peak output power in 65 nm CMOS,” in 2013
European Microwave Conference, 2013, pp. 536–539, doi: 10.23919/EuMC.2013.6686955.
[28] H. Bello, L. Pantoli, H. J. Ng, D. Kissinger, and G. Leuzzi, “Low phase‐noise high output power 176‐GHz voltage‐controlled
oscillator in a 130‐nm BiCMOS technology,” IET Microwaves, Antennas & Propagation, vol. 13, no. 14, pp. 2490–2494, Nov.
2019, doi: 10.1049/iet-map.2019.0397.
BIOGRAPHIES OF AUTHORS
Oluseun Damilola Oyeleke is a lecturer 1 at the Nile University of Nigeria. He is
a graduate of Electrical engineering from Bayero University Kano and also has his Meng from
the Nigeria Defence Academy in Electronics and communications. His research interest is in
the areas of microwave technology, solid-state electronics, and machine learning for
telecommunication and health applications. He can be contacted at email:
[email protected] or [email protected].
Design of a 175 GHz SiGe-based voltage-controlled oscillator with greater … (Oluseun Damilola Oyeleke)
113
BiCMOS,” in 2021 International Conference on Electrical, Computer, Communications and Mechatronics Engineering
(ICECCME), Oct. 2021, pp. 1–4, doi: 10.1109/ICECCME52200.2021.9591117.
[6] R. Bindiganavile and A. Tajalli, “A controllable KVCO ring VCO topology,” in 2021 IEEE International Midwest Symposium on
Circuits and Systems (MWSCAS), Aug. 2021, pp. 732–736, doi: 10.1109/MWSCAS47672.2021.9531824.
[7] J. Raab et al., “Ultrafast two-dimensional field spectroscopy of terahertz intersubband saturable absorbers,” Optics Express, vol.
27, no. 3, pp. 2248–2257, Feb. 2019, doi: 10.1364/OE.27.002248.
[8] M. B. Wallace, A. Wax, D. N. Roberts, and R. N. Graf, “Reflectance spectroscopy,” Gastrointestinal Endoscopy Clinics of North
America, vol. 19, no. 2, pp. 233–242, Apr. 2009, doi: 10.1016/j.giec.2009.02.008.
[9] Z. Vafapour, A. Keshavarz, and H. Ghahraloud, “The potential of terahertz sensing for cancer diagnosis,” Heliyon, vol. 6, no. 12,
pp. 1–8, Dec. 2020, doi: 10.1016/j.heliyon.2020.e05623.
[10] P.-Y. Chiang, O. Momeni, and P. Heydari, “A 200-GHz inductively tuned VCO with-7-dBm output power in 130-nm SiGe
BiCMOS,” IEEE Transactions on Microwave Theory and Techniques, vol. 61, no. 10, pp. 3666–3673, Oct. 2013, doi:
10.1109/TMTT.2013.2279779.
[11] O. Momeni and E. Afshari, “High power terahertz and millimeter-wave oscillator design: a systematic approach,” IEEE Journal
of Solid-State Circuits, vol. 46, no. 3, pp. 583–597, Mar. 2011, doi: 10.1109/JSSC.2011.2104553.
[12] S. Voinigescu, High-frequency integrated circuits. Cambridge: Cambridge University Press, 2013.
[13] M. Schroter et al., “The EU DOTSEVEN project: overview and results,” in 2016 IEEE Compound Semiconductor Integrated
Circuit Symposium (CSICS), Oct. 2016, pp. 1–4, doi: 10.1109/CSICS.2016.7751070.
[14] F. Ahmed, M. Furqan, B. Heinemann, and A. Stelzer, “0.3-THz SiGe-based high-efficiency push–push VCOs with> 1-mW peak
output power employing common-mode impedance enhancement,” IEEE Transactions on Microwave Theory and Techniques,
vol. 66, no. 3, pp. 1384–1398, Mar. 2018, doi: 10.1109/TMTT.2017.2767593.
[15] A. Bhat and N. Krishnapura, “26.3 A 25-to-38 GHz, 195 dB FoMT LC QVCO in 65 nm LP CMOS using a 4-port dual-mode
resonator for 5G radios,” in 2019 IEEE International Solid- State Circuits Conference-(ISSCC), Feb. 2019, pp. 412–414, doi:
10.1109/ISSCC.2019.8662502.
[16] L. Pantoli, H. Bello, G. Leuzzi, H. J. Ng, and D. Kissinger, “SiGe sub-THz VCOs design approach for imaging applications,” in
2020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC), Jul. 2020, pp. 1–3,
doi: 10.1109/INMMiC46721.2020.9160077.
[17] C.-C. Chuang and H.-K. Chiou, “A low phase noise X band class E power VCO in 0.25 μm GaN/SiC technology,” in 2021 IEEE
International Symposium on Radio-Frequency Integration Technology (RFIT), Aug. 2021, pp. 1–3, doi:
10.1109/RFIT52905.2021.9565205.
[18] G. Gonzalez, Foundations of oscillator circuit design. Norwood: Artech House, 2007.
[19] H. Wang, J. Chen, J. T. S. Do, H. Rashtian, and X. Liu, “High-efficiency millimeter-wave single-ended and differential
fundamental oscillators in CMOS,” IEEE Journal of Solid-State Circuits, vol. 53, no. 8, pp. 2151–2163, Aug. 2018, doi:
10.1109/JSSC.2018.2837863.
[20] S. Kong, H. Liu, Y. Shen, Y. Wu, Y. Yu, and K. Kang, “A 3.65-4.10 GHz class-C VCO with 189.1 DBC/hz FoM based on low
electromagnetic coupling,” in 2021 International Conference on Microwave and Millimeter Wave Technology (ICMMT), May
2021, pp. 1–3, doi: 10.1109/ICMMT52847.2021.9618554.
[21] Y. Z. M. Ibrahim, M. A. Y. Abdalla, and A. N. Mohieldin, “A 197 FOMT VCO with 34% tuning range for 5G applications in
45nm SOI technology,” in 2022 IEEE Radio and Wireless Symposium (RWS), Jan. 2022, pp. 108–110, doi:
10.1109/RWS53089.2022.9719977.
[22] P. Maheshwari, P. K. Sadhu, M. Deharia, N. Nambath, and S. Gupta, “A quadrature-phase voltage controlled oscillator for offset
phase and frequency compensation,” in 2018 31st International Conference on VLSI Design and 2018 17th International
Conference on Embedded Systems (VLSID), Jan. 2018, pp. 177–180, doi: 10.1109/VLSID.2018.58.
[23] F. Vogelsang, D. Starke, J. Wittemeier, H. Rucker, and N. Pohl, “A highly-efficient 120 GHz and 240 GHz signal source in a
SiGe-technology,” in 2020 IEEE BiCMOS and Compound Semiconductor Integrated Circuits and Technology Symposium
(BCICTS), Nov. 2020, pp. 1–4, doi: 10.1109/BCICTS48439.2020.9392945.
[24] Y. Zhao, B. Heinemann, and U. R. Pfeiffer, “Fundamental mode colpitts VCOs at 115 and 165-GHz,” in 2011 IEEE
Bipolar/BiCMOS Circuits and Technology Meeting, Oct. 2011, pp. 33–36, doi: 10.1109/BCTM.2011.6082744.
[25] D. Fritsche, S. Li, N. Joram, C. Carta, and F. Ellinger, “Design and characterization of a 190-GHz voltage-controlled oscillator,”
in 2016 46th European Microwave Conference (EuMC), Oct. 2016, pp. 493–496, doi: 10.1109/EuMC.2016.7824387.
[26] U. Ali, G. Fischer, and A. Thiede, “Low power fundamental VCO design in D-band using 0.13 μm SiGe BiCMOS technology,”
in 2015 German Microwave Conference, Mar. 2015, pp. 359–362, doi: 10.1109/GEMIC.2015.7107827.
[27] B. Khamaisi and E. Socher, “A 159-169 GHz frequency source with 1.26 mW peak output power in 65 nm CMOS,” in 2013
European Microwave Conference, 2013, pp. 536–539, doi: 10.23919/EuMC.2013.6686955.
[28] H. Bello, L. Pantoli, H. J. Ng, D. Kissinger, and G. Leuzzi, “Low phase‐noise high output power 176‐GHz voltage‐controlled
oscillator in a 130‐nm BiCMOS technology,” IET Microwaves, Antennas & Propagation, vol. 13, no. 14, pp. 2490–2494, Nov.
2019, doi: 10.1049/iet-map.2019.0397.
BIOGRAPHIES OF AUTHORS
Oluseun Damilola Oyeleke is a lecturer 1 at the Nile University of Nigeria. He is
a graduate of Electrical engineering from Bayero University Kano and also has his Meng from
the Nigeria Defence Academy in Electronics and communications. His research interest is in
the areas of microwave technology, solid-state electronics, and machine learning for
telecommunication and health applications. He can be contacted at email:
[email protected] or [email protected].
ISSN: 2252-8776
Int J Inf & Commun Technol, Vol. 12, No. 2, August 2023: 103-114
114
Aliyu Danjuma Usman is a Professor of Telecommunications Engineering from
Ahmadu Bello University, Zaria. He obtained his Ph.D. in Electrical and Electronics
Engineering, from Universiti Putra, Malaysia (UPM) in 2011. Master of Electrical
Engineering from Bayero University Kano (BUK) in 2006. B.Sc. in Computer Engineering
from MAAUN in 2018. He is a recipient of numerous merit and recognition awards. His work
experience span from industries to academia. He worked with the Polytechnic sector and rose
to the rank of Chief lecturer before joining the University. He published over 130 peer-
reviewed National and International Journals/Conferences and has authored many books and
book Chapters. Currently, he has over 310 citations and 10 h-index. He is a recipient of many
research grants locally and internationally. He has so far graduated over 30 M.Sc, 10 Ph.D.
students and many under his supervision. He served as Technical Committee Chair and
member of numerous local and international conferences. Prof. Usman is a member of many
national and international professional bodies which include; IEEE, COREN, MNSE, and
MSESN. Research interest: teletrafic engineering, antenna radiation, wireless
communications, microwave engineering terahertz frequencies, and RF EMF effect. He can be
contacted at email: [email protected]; aliyuusman1@gmail.
Kabir Ahmad Abubilal is a Professor at the Department of Telecommunications
Engineering, Ahmadu Bello University, Zaria. He received his B.Engr, M.Sc, and Ph.D.
Degrees from Department of Electrical Engineering, Ahmadu Bello University Zaria, Nigeria,
in 2006, 2009, and 2015, respectively. He has several publications and Conference
proceedings. He won the best student paper award at the 2013 International Conference of
Electrical and Electronics Engineering at the World Congress of Engineering, London 2013.
His research interests are wireless and mobile communications, microcontrollers and
applications, and digital electronics. He can be contacted at email: [email protected];
[email protected].
Habeeb Bello holds a Ph.D. in Electrical, Electronics, and Information
Engineering from the University of L’Aquila, Italy in 2019, a Master’s degree in
Communication Engineering from The University of Manchester, United Kingdom in 2015,
and he also worked as a guest research scientist in the circuit department, Innovation for High-
performance microelectronics (IHP), Frankfurt (Oder), Germany and Technical University of
Denmark (DTU), Denmark. Habeeb received his B.Eng in Electrical and Computer
Engineering from the Federal University of Technology, Minna, Nigeria. His research interest
includes communications systems, radar systems, antenna design, millimeter-wave, and THz
integrated circuits for imaging and communication applications. He is currently a staff of the
Department of Electronics and Telecommunications Engineering, Ahmadu Bello University,
Zaria, Nigeria. He can be contacted at email: [email protected].
Olabode Idowu-Bismark holds a B.Eng. in Electrical and Electronics
Engineering from the University of Benin, in Nigeria. M.Sc degree in Telecommunications
Engineering from Birmingham University UK and a Ph.D. in Information and Communication
Engineering from Covenant University, Ota, Nigeria. Olabode has worked in various
companies including Logic Sciences Limited, Basscomm, and Primotek Systems Limited as a
senior engineer, project manager, and executive director. He is a member of the Nigerian
Society of Engineers, MIEEE, and a COREN Registered Engineer. His research interest is in
the area of mobile communication, mmWave, and MIMO communication. He has published
many scientific papers in international peer-reviewed journals and conferences. He can be
contacted at email: [email protected].
Int J Inf & Commun Technol, Vol. 12, No. 2, August 2023: 103-114
114
Aliyu Danjuma Usman is a Professor of Telecommunications Engineering from
Ahmadu Bello University, Zaria. He obtained his Ph.D. in Electrical and Electronics
Engineering, from Universiti Putra, Malaysia (UPM) in 2011. Master of Electrical
Engineering from Bayero University Kano (BUK) in 2006. B.Sc. in Computer Engineering
from MAAUN in 2018. He is a recipient of numerous merit and recognition awards. His work
experience span from industries to academia. He worked with the Polytechnic sector and rose
to the rank of Chief lecturer before joining the University. He published over 130 peer-
reviewed National and International Journals/Conferences and has authored many books and
book Chapters. Currently, he has over 310 citations and 10 h-index. He is a recipient of many
research grants locally and internationally. He has so far graduated over 30 M.Sc, 10 Ph.D.
students and many under his supervision. He served as Technical Committee Chair and
member of numerous local and international conferences. Prof. Usman is a member of many
national and international professional bodies which include; IEEE, COREN, MNSE, and
MSESN. Research interest: teletrafic engineering, antenna radiation, wireless
communications, microwave engineering terahertz frequencies, and RF EMF effect. He can be
contacted at email: [email protected]; aliyuusman1@gmail.
Kabir Ahmad Abubilal is a Professor at the Department of Telecommunications
Engineering, Ahmadu Bello University, Zaria. He received his B.Engr, M.Sc, and Ph.D.
Degrees from Department of Electrical Engineering, Ahmadu Bello University Zaria, Nigeria,
in 2006, 2009, and 2015, respectively. He has several publications and Conference
proceedings. He won the best student paper award at the 2013 International Conference of
Electrical and Electronics Engineering at the World Congress of Engineering, London 2013.
His research interests are wireless and mobile communications, microcontrollers and
applications, and digital electronics. He can be contacted at email: [email protected];
[email protected].
Habeeb Bello holds a Ph.D. in Electrical, Electronics, and Information
Engineering from the University of L’Aquila, Italy in 2019, a Master’s degree in
Communication Engineering from The University of Manchester, United Kingdom in 2015,
and he also worked as a guest research scientist in the circuit department, Innovation for High-
performance microelectronics (IHP), Frankfurt (Oder), Germany and Technical University of
Denmark (DTU), Denmark. Habeeb received his B.Eng in Electrical and Computer
Engineering from the Federal University of Technology, Minna, Nigeria. His research interest
includes communications systems, radar systems, antenna design, millimeter-wave, and THz
integrated circuits for imaging and communication applications. He is currently a staff of the
Department of Electronics and Telecommunications Engineering, Ahmadu Bello University,
Zaria, Nigeria. He can be contacted at email: [email protected].
Olabode Idowu-Bismark holds a B.Eng. in Electrical and Electronics
Engineering from the University of Benin, in Nigeria. M.Sc degree in Telecommunications
Engineering from Birmingham University UK and a Ph.D. in Information and Communication
Engineering from Covenant University, Ota, Nigeria. Olabode has worked in various
companies including Logic Sciences Limited, Basscomm, and Primotek Systems Limited as a
senior engineer, project manager, and executive director. He is a member of the Nigerian
Society of Engineers, MIEEE, and a COREN Registered Engineer. His research interest is in
the area of mobile communication, mmWave, and MIMO communication. He has published
many scientific papers in international peer-reviewed journals and conferences. He can be
contacted at email: [email protected].
Categories
DesignDownload
Download Slideshow Get the original presentation fileQuick Actions
Statistics
- Views 0
- Slides 12
- Age 55 days
Related Slideshows
1
MGV Residential Design projects for different clients, including a New Mexico Adobe project-1-.pdf
mannyvesa
26 views
16
EUNITED_Advocacy and Public Engagement through Visual Media
GeorgeDiamandis11
31 views
31
DESIGN THINKINGGG PPT 2 TOPIC IDEATION.pptx
HibaZaidi2
24 views
36
DESIGN THINKING CHAPTER 1 PPTT PPT 1.pptx
HibaZaidi2
28 views
112
Hinduism and Its History - PowerPoint Slides.pptx
ConorMcCormack10
24 views
20
Service Attributes of Manufactured Parts.pptx
MustafaEnesKrmac
24 views